Transformer-rheostat control device



June 14, 1932. CUFF 1,863,267

' TRANSFORMER RHEOSTAT CONTROL DEVICE Filed June 25, 1930 2 Sheets-Sheetl d5 Jam-SE. Cq/f J. E. CUFF 1930 2 Sheets-Sheet 2 June 14, 1932TRANSFORMER RHEOSTAT CONTROL DEVICE I Fild June 23,

Patented June 14, 1932 UNITED STATES PATENT OFFICE JAMES E. CUFF, OIIIIN'SDALE, ILLINOIS, ASSIGNOR "1'0 AMERICAN IELYER- MFG. 00., 0F

\ CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS TRANSFOBMER-RHEOSTATCONTROL DEVICE Application filed June 23,

This invention relates to control transformer-rheostats for toy electricrailways and other electrically operated toys or devices, and has forits general object to provide a transformer-rheostat of attractiveappearance and of generally improved construction designed to reduceahigh voltage alternating current to selective lower voltages suit ablefor the operation of toys or devices of the character mentioned. I

Another object of the invention is to provide a transformer-rheostataccording to which all operating parts thereof with the exception ofanad'ustment knob are housed within a box provided with a removablecover, the cover carrying the switch or rheostat mechanism whereby thelatter is removable as a unit with the cover'and when so removed iscompletely exposed for convenient access for any purpose desired, thisfeature being particularly desirable from a practical and economicalmanufacturing and assembly standpoint.

Another object of the invention is to provide a transformer-rheostat ofthe character mentioned which is of relatively simple, inexpensiveconstruction, strong and durable, and which is thoroughly reliable andefficient 1n use.

With the foregoing and other objects in view which will more readilyappear as the nature of the invention is better understood, the sameconsists in the novel features of construction, combination andarrangement of parts as will be hereinafter more fully described,illustrated in the accompanying drawings and defined in the appendedclaims.

In the drawings wherein like characters of reference denote correspodingparts in the different views:

Figure 1 is a top plan view of a transformersrheostat constructed inaccordance with the invention.

'Figure2 is an elevation looking towards the inner face of thecover andshowing the rheostat mechanism carried by the cover.

Figure. 3 is an enlarged sectional view through the cover and therheostat mechanism; and

Figure 4 is a wiring diagram of the device.

1930. Serial no. 433,330.

According to the practical embodiment of the invention illustrated inthe drawings, a box 10 is provided within which are arranged a primarywinding 11 and a secondary winding 12, the latter being connected atsuitably spaced intervals by wires 13, 14, 15 and 16 with binding postsB, C, D and E shown in Figure 4 of the drawings and understood, ofcourse, to be carried by the box at suitable locations to selectivelyhave connected therewith one of a pair of wires to complete a circuitthrough a track, semaphore or the like.

Referring further to Figure 4 of the drawings, it will be observed thatanother binding post A is provided and that same is" connected with aswitch arm 17 by a wire 18. At 19, 20, 21,22, 23, 24 and 25 aredesignated contacts which are adapted to be selectively engaged by saidswitch arm, these contacts with the exception of the contact 19, whichis an idle or oil contact being connected to the secondary winding 12 atsuitably spaced points by wires 20, 21, 22, 23', 24 and 25,respectively.

The binding post A is adapted to have connected therewith the other ofthe pair of wires to complete the circuit through the track, semaphoreor the like, this wire being designated as 26 and'the wire for selectiveconnection with the binding posts B, C, D or E being designated as 27.Thus, manifestly, regardless of which of the binding posts B, C, D or Ethe wire 27 may be connected with, the voltage in the circuit betweenthe bindin post A and the particular binding post B, D or E with whichthe wire 27 is connected, is capable of being varied by movement of theswitch arm 17 into engagement with different ofthe contacts 20, 21, 22,23, 24 and 25, since by engaging said switch arm with different of saidcontacts, the number of effective turns in the secondary winding 12 maybe increased or diminished.

In the particular embodiment of the invention herein illustrated, thebinding post E is connected by the, wire 16 to one end of thesecondary'winding 12, and the contact 25 is connected by the wire 25" tothe other end of said winding, the Wires 15, 14 and 13 being connectedwith said winding at points spaced successivel inwardly from the pointof connection of t e wire 16 with the winding, and the wires 24, 23',22', 21' and 20 likewise being connected with said winding tact 20, thecircuit through the bindin posts A-B will include a minimum num r ofturns of the winding 12 for that circuit and the volta e for suchcircuit will be a minimum as etermined b the number of turns in thesecondary winriingbetween the wires 13 and Therefore, if the switch armis moved'into eng ement with the next contact 21', the num r ofeffective turns in the winding 12 will'be increased by an amount equalto the number of turns in the winding between the wires 20' and 21 andthe voltage will be correspondingly increased. In the same we thevoltage m'the circuit AB will be fu r increased as the switch arm ismoved successively into engagement with the contacts 22, 23, 24 and 25,maximum voltage for the particular circuit under consideration beingobtained when the switch arm is engaged with the last contact 25.

On the other hand, if the wire 27 is connected with the binding post C,the number of effective turns in the winding 12 for the circuit AC willbe increased over the'number of effective turns of said winding for thecircuit AB, for any-position of the switch arm 17 by an amount equal tothe number of turns in the winding 12 between the wires 13 and 14 andthe voltage for the circuit A-C will be correspondingly increased overthe voltage of the circuit AB for any given position of the switch arm.In the same way, higher voltage circuits obviously are obtainable byconnecting the wire 27 with the binding posts 'D or E, and as ismanifest, by predetermining the number of turns of the winding 12between the various binding post and contact wires connected therewith,minimum and maximum voltages for each circuit, and the voltage variationin each circuit effected by movement of the switch arm from one toanother of its related contacts, may be readily predetermined to adaptthe device to 'any'particular use.

Referring now to Figures 1 to 3 of the drawings, wherein is illustrateda practical embodiment of the invention diagrammatically shown in Figure4, it will be observed that a cover 28 is provided for detachableengagement with the box 10, and that said cover to this end is providedwith a depending marginal flange 29 adapted to fit around the topportion of the box, said flange being provided with suitable formations30 for detachable interfitting engagement with companion formations onthe box to retain the cover normally assembled with the box.

Disposed in a suitable'location against the under face of the cover 28is a sheet 31 of insulating material, directly below which is arranged asecond sheet of insulating material 32, the two sheets being secured tothe cover in any suitable or desired manner, as, for example, by rivets33. The contacts 19, 20, 21, 22, 23, 24 and 25 in the form of eyeletsfor example, are carried by the insulatin sheet 32 and are insulatedfrom the cover day the insulating sheet 31.

Extending through alined openings in the insulating sheets 31, 32 andthrough an o ning in the cover 28, is a shaft 34 whic .is freelyrotatable with respect to the cover and said insulating sheets andwhich, preferably, is of square or other polygonal cross section.Mounted on this shaft for rotation therewith and disposed at the outsideof the cover 28 is a pointer 35 and a fluted or serrated finger gripknob 36. Also mounted on said shaft for rotation therewith, but disposedinside of the cover, is the switch arm 17 and a leaf spring'37, theswitch arm being disposed adjacent to the insulating sheet 32 wherebyits free'end is adapted for movement into engagement with the differentcon tacts 19, 20, etc. b rotation of the shaft 34, and the spring 3being disposed between said switch arm and a screw 38 threaded into theinner end of the shaft whereby the parts are held in assembly and ayielding pressure exerted against the switch arm to assure good. contactthereof with the contacts 19, 20, etc.

On the shaft 34, against the switch arm 17, ,is mounted a clip 39 withwhich the wire 18 leading to the binding post A is connected, whilestruck outward from the switch arm is a tongue 40 which enters anopening 41 in the leaf spring 37 to hold said spring in operativerelationto the switch arm. In this connection it will be observed thatthe spring 37 is bent into substantially shallow V-sha and has its endsin engagement with e switch arm at opposite sides of the shaft 34, itsintermediate portion being engaged by the screw 38, 'or more correctlystated, by a washer 42 disposed between the screw and the spring,whereby ood contact of the switch arm with both 0 ip 39 and the switchcontacts is assured.

The pointer 35 is disposed inradial alinement with the switch arm 17 soas to indicate at the outside of the cover the angular position of theswitch arm which is concealed beneath the cover, and in this connectiona feature of the invention resides in the provision of a chart 43located on the outer face of the cover to indicate the exact voltage inthe circuit, according to the position of the ointer 35, and accordingto the particular inding post, B, C, D or E with which the wire 27 maybe connected. That is to sa the chart 43, which may be formed directl onthe cover or on a sheet separate from the cover and suitably securedthereto, is in- 5 elusive of a circumferential division 44 related toeach contact 20, 21, etc. and a radial division 45 related to eachbinding post B, C, D and E, the circumferential divisions of each radialdivision having marked therein the voltage that is obtained in therespective circuits A--B, A-C, A-D and AE when the switch arm 17 isengaged with any particular contact 20, 21 etc. Thus, knowing with whichof the binding posts the wire 27 is connected, the person operating theknob 36 may ascertain at a glance the exact voltage in the circuit forany position of the switch arm simply by noting to which of thecircumferential divisions 44 of the chart the pointer 35 points to andby reading the voltage in the proper radial division 45.

The chart 43 is formed of a suitable attractive shape and preferably issurrounded by a protective beading 46 pressed outward from the metal ofthe cover.

Without further description it is thought that the features andadvantages of the invention will be readily apparent to those skilled inthe art, and it will of course be understood that changes in the form,proportion and minor details of construction may be resorted to, withoutdeparting from the spirit of the invention and the scope of the appendedclaims.

I claim:

1. In a device of the character described, a I box cover, a shaftextending through said cover, an operating member on said shaft outsideof said cover, a series of contacts within the cover, a switch arm onsaid shaft for cooperation with said contacts, an abuthis signature.

JAMES E. CUFF.

ment on said shaft, and a leaf spring between said abutment and saidswitch arm to urge the latter against said contacts, said leaf springhaving an opening therein and said switch arm having a tongue projectingtherefrom into said opening.

2. In a device of the character described,

a box cover, a shaft extending through said cover, an operating memberon said shaft outside of said cover, a series of contacts within thecover, a switch arm on said shaft for cooperation with said contacts, anabutment on said shaft, and a leaf spring between said abutment and saidswitch arm to urge the latter against said contacts, said leaf springbeing of shallow V-shape and bearing at its ends against said switch armto opposite sides of said shaft, respectively.

3. In a device of the character described, a switch comprising contactsand a cooperating switch arm, a shaft on which said switch arm ismounted, and means to urge the v switch arm in the direction of thecontacts, said means comprising a leaf spring mount-

